This study， based on the panel data of A?share listed manufacturing enterprises from 2008 to 2022， constructs an evaluation system to meet their high?quality development level that is more in line with its connotation. The impact of the Belt and Road Initiative on the high?quality development of China's manufacturing enterprises is examined by applying the difference?in?difference method. It is found that the initiative significantly promotes our high?quality development in the sectors in general， which remains robust after matching the propensity scores and excluding other policies effects in the same period. Mechanism analysis shows that the initiative elevates the high?quality development to new heights through the supply chain integration effect， the financing constraint alleviation effect， and the pressure innovation effect， respectively. Heterogeneity analysis reveals that the initiative contributes more to the state?owned enterprises， enterprises in the central and western regions， and enterprises with higher capacity utilization rates in terms of high-quality development.